Humidifiers



Feb. 7, 1967 G. A. KELLOGG 3,302,631

HUMIDIFIERS Filed April 26, 1965 INVENTOR. GZEN/VA. KELLOGG ATTV.

United States Patent 3,302,631 HUMIDIFERS Glenn A. Kellogg, 55237 Moss Road, South Bend, Ind. 46628 Filed Apr. 26, 1965, Ser. No. 450,634 3 Claims. (Cl. 126-113) This invention relates to humidifiers, and is particularly concerned with an improved evaporator pan, and, a control means which may be placed either within the heating unit or at an external location.

This invention discloses in a preferred embodiment a novel structure and construction of a humidifier comprising a plurality of stacked water reservoirs or evaporator pans mounted on an upright tube means and positioned in the air path of a forced air furnace or the like. One of the pans is in direct contact with the firepot or heat exchange of the furnance and water delivered to the pan, which is regulated to a substantially low level, is quickly vaporized by the heat of the firepot.

The use of humidifiers in present day construction of homes, office buildings and the like is widespread. Such humidifiers are normally placed within the heating system and are associated and function with the system. The heating of fresh, outside air at a relatively low temperature during the seasons of the year when artificial heat is required greatly reduces the humidity of the air. Consequently, heating of the air and placing the same within a home or office creates a flow of air which is exceedingly dry. The circulation of dry air has a relative cooling effect which is undesirable and which may be remedied by increasing the moisture in the air by the use of a humidifier. The insertion of a humidifier in the heating system thereby increases the moisture of the air passing through the system to a level of comfort.

Present day humidifiers utilize numerous means to add moisture to the air via the forced air circulation of a heating system. Such humidifiers use various types of external heating sources to heat the water in the evaporator pan to a predetermined temperature to thereby assist evaporization or vaporization, depending on the particular device and how it is constructed to perform.

Many humidifiers in present use in forced air heating systems merely employ a simple evaporator pan within the confines of the furnace bonnet or casing with a means to provide a constant water level within the pan. Air forced past the pan will cause the water to evaporate into the air thereby increasing the moisture content of the air. Such humidifiers are basically ineffective. Plates inserted in the evaporator pan are often utilized to increase the surface area of the water in exposure to the passing forced air which is subsequently directed into the heating ducts. This provision adds little to the efficiency and effectiveness of the simple evaporator pan.

The primary object of the instant invention is to provide a humidifier for use with a forced air heating system having a plurality of improved evaporator pans which are constructed and arranged in a novel manner and placed Within proximity of the heat exchange of the furnace to thereby provide both evaporization and vaporization of the water therein for increasing the moisture content of the air passing through the heating system.

Still another object is to provide a humidifier having a base evaporator pan which is constructed of a material having a high thermal conductivity and is placed in direct contact with the heat exchange or firepot of the heating system with which it is associated whereby the water supplied to the pan may be readily vaporized.

It is a further object to provide a humidifier which maintains a minimum controlled amount of water in a base evaporator pan, which water is rapidly vaporized by ice the heat exchange with which it is in contact, upon heating of the said heat exchange.

It is a further object to provide a humidifier which maintains a relatively minute amount of water in the evaporator pan which rapidly vaporizes when the heat exchange is fired and reaches a predetermined operating temperature and further contains additional evaporator pans which are constantly kept filled with water by a control means.

Still a further object is to provide a humidifier having a plurality of stacked evaporator pans whereby air passing between the stacked pans enables the humidity of the air to be increased due to the additional surface area of the water in contact with the air which is forced around the pans.

Still a further object is to provide a humidifier having a plurality of stacked evaporator pans which is efficient in operation and which has a minimum of mechanically functioning components thereby being less succeptable to liming and mineral deposit malfunction.

Still a further object is to provide a humidifier having a control means for maintaining a predetermined level of water in an evaporator pan, the location of which may be either inside the bonnet, or casing, of the furnace, or, outside the furnace bonnet.

Still another object of the instant invention is to provide a humidifier which has no mechanically operating parts in the pan structure.

Another object is to provide a humidifier which uses a minimum of parts, is simple to construct and which is economical to maintain and easy to service.

These and other objects of the invention will become apparent from the following specification, which when taken in conjunction with the accompanying drawing, illustrates a preferred form of the invention.

The drawing illustrates a preferred embodiment of the invention in a typical installation showing an elevational view of the improved evaporator pan placed within the confines of the bonnet of a forced air heating system and showing the furnace and control means in sectional view.

With reference to the drawing, a conventional forced air furnace, generally designated by reference numeral 10, includes a bonnet or casing 12 in communication with heat ducts 14, which direct the flow of heated air into the respective areas to be heated, and a firepot or heat source 16. The firepot 16 may be heated by any conventional heating means such as coal, or may include a gas or oil burner arrangement, not shown. To assist the circulation of heated air to the areas which are remote from the furnace, a blower or fan, not shown, is often placed within the confines of the casing 12 to thereby force the air, heated by firepot 16, through the ducts 14.

The humidifier assembly 18 includes a lower or base evaporator pan 22 which is so constructed and positioned that any overflow from evaporator pans 20, which are filled with water under normal operating conditions, and, are positioned directly above pan 22, will be deposited in the later pan. The regulation of a specific water level, which is controlled only in pan 22, is accomplished only by permitting overflow from pans 20 to be deposited into pan 22. Base pan 22 is constructed of a material having a high thermal conductivity, such as copper or aluminum, for reasons to be hereinafter explained. The pan 22 is also constructed so that the bottom contour is complementary with the firepot on which it rests so that a maximum amount of heat is transferred to the pan. The pan 22 must be maintained in a horizontal position. The pan 22 is of thin wall construction so that water deposited therein is quickly vaporized by the firepot when the same is heated, to be hereinafter explained. Pan 22 has a central recessed portion 24 which accepts a hollow metallic tube means 26 which is attached to the pan and projects perpendicular thereto. Tube means 26 passes through evaporator pans 20 and the tube is attached to all the said pans by soldering or other suitable means to provide a watertight connection so that pans 20 may be filled with water without leakage occurring between the tube and pans. The tube 26 is centrally located with respect to all the pans so that the pans and tube, which comprise an assembly, will be substantially symmetrical and will maintain balance when the pans 20 are filled with water. An overflow tube, not shown, may be placed at a predetermined level in pan 22 and extend to an external location if so desired.

Evaporator pans 20 are placed one above the other in a stacked arrangement and attached to tube means 26 whereby the pan above any respective pan is smaller in overall size of periphery so that any overflow will be deposited in a respective lower pan and eventually all overflow will be deposited in base evaporator pan 22, which maintains a controlled water level. The pans 20 and 22 may be either circular, rectangular, or square, provided sufficient overlap exists between the stacked pans to permit overflow from any one pan into a lower pan. Pans 20 are of rigid construction to enable them to be filled with water and whereby the stacked arrangement of pans will resist any vibration which may exist in the heating system so that spilage of water will be eliminated. It is noted that heat from firepot 16 will rise through the tube means 26 to heat the water in pans 20 to assist the evaporization process since the pans 20 are normally filled with water and the tube is in contact with the water in each pan for the respective height of the pan, as clearly shown in the drawing.

A control assembly means 36 regulates the water level 23 desired in the base pan and includes a float chamber 38 having a cover means 40. A float member 42 having a shaft 44 extending therefrom is positioned in the chamber. The float member 42 should be of sufficient size to provide ample buoyance for effectively actuating a switch, as explained below, to thereby close the circuit leading into the switch 48. Shaft 44 may be guided by additional guide means, not shown, so that true vertical movement of the shaft is assured whenever the float member 42 is displaced within chamber 38. A microswitch 48 it attached to a bracket 50 which, in turn, is atfixed to chamber 38 by any suitable means. Switch 48 has a yoke shaped resilient switch actuating member 51 which straddles shaft 44 and is positioned to be operatively engaged by adjusting nut 46 when the water in base pan 22 goes below a predetermined level, to be hereinafter explained. Upon depressing of member 51 by nut 46, the microswitch plunger 52 will close the switch 48 in a well known manner. A connecting tube 30 joins chamber 38 and pan 22 and provides a means for water to flow from the said pan 22 into the said chamber so that the water level in pan 22 is that of the chamber, i.e., levels 23 and 54 are the same. An indented portion 28 in pan 22, which provides a vertical mounting area for the tube 30, facilitates a connection between the said pan and tube. The tube 30 is connected to pan 22 and chamber 38 by lock nuts 32, 34, respectively, which are threadedly engaged onto fittings, not shown, which protrude from the pan 22 and chamber 38 so that the flared ends of the tube may be drawn tight with respect to the fittings by the lock nuts in a well known manner. The tube 30 may also be soldered or brazed to the pan 22 and chamber 38 if so desired. The only import being that there be a leakproof connection formed and that water may freely pass from the pan 22 to the chamber 38 so that the proper level of water may be maintained in the pan 22.

It is noted that tube 30 is shown in broken lines in the drawing. This identification is made to show that the control assembly means 36 may be placed within the casing 12 of the furnace or may be externally located if so desired. Also, the tube 30 should be of sutficient diameter to prevent mineral deposits from clogging the tube and thereby impede the water level regulation. In certain installations, because of the restriction in space and also the heat level, it is often necessary to remove the control means outside the furnace bonnet.

To maintain water in the pans 20 and 22, a supply of water under pressure is delivered via tube 56 to a valve 58 which is normally in a closed position. A solenoid 62, when actuated, opens the valve 58 to permit water to pass therethrough to be deposited, via tube 60, into the top pan of the humidifier. A humidistat 66, normally positioned in a remote area to be heated above floor 68, performs the function of closing the circuit in one of the electrical lines 64 to the microswitch 48 when the humidity in the air is below a predetermined percentage.

The drawing is shown to illustrate the humidifier and its associated elements whereby the heating unit 10, which includes the humidifier 18 and control means 36 therein, is normally located in a basement area and the humidistat 66 is placed in a remote area to be heated, normally above the basement area, and separated by floor 68 in a conventional manner.

Operation of the humidifier is quite foolproof and simple. A source of conventional electrical current is supplied via electrical lines so that a continuous circuit may be completed from one line to the other through the humidistat 66, microswitch 48 and solenoid 62. In order to complete the circuit, the humidistat must be actuated, due to a lack of humidity at its location, and, the water level 23 in pan 22 must be below a predetermined level to thereby close the microswitch 48 so that the circuit to the solenoid 62 is completed. Obviously, when either the water level 23 is normal, and/or the humidity is at the desired predetermined percentage, the circuit will not be completed. At this time, when the circuit is completed, water will be allowed to flow through the valve 58 and tube 60 to be deposited in the top evaporator pan. As the top pan fills, it will overflow into a lower pan and this will continue until water will subsequently be deposited in the base pan 22. The water level in base pan 22 is carefully regulated by the control means 38 so that the level never exceeds a fraction of an inch, normally less than A; of an inch. This extremely low level is imperative as it permits the water in pan 22 to be rapidly vaporized when it is admitted into the pan when firepot 16 is heated since the pan is of high thermal conductivity, therefore it becomes excessively hot and promotes rapid vaporization of the water therein. Once the minute water level in pan 22 is maintained, and noting that the water level in float chamber 38 is the same as the water level in the said pan, the adjusting nut 46 will be positioned free of switch actuating member 51 to thereby open the microswitch 48 and break the circuit to deenergize solenoid 62 so that valve 58 will return to its normally closed position. It is noted that in order to acquire a predetermined water level in pan 22, all of the pans 20 must first be filled since the water entering pan 22 must first pass over all the stacked pans 20. With reference to float chamber 36, it is noted that the float member 42 should be of large diameter, and ample buoyance, so that it may transmit minute changes in water level to the microswitch. Since only small quantities of water are admitted into the evaporator pans at any given time, the necessity for an extremely low water level in base pan 22 is paramount in the proper functioning of the humidifier since the high heat transfer of the base pan 22, coupled with the fact that the pan is located on the firepot 16, rapidly vaporizes water therein when the firepot is heated to thereby increase the efficiency of the humidifier. Further, the numerous pans of water, which are partially heated by the tube 26, and also the overflowing of water from one pan into a lower pan, increases the surface area of the water in contact with the forced air to also g e additional amounts of moisture to the forced air as it passes the area of the humidifier 18 prior to being directed through ducts 14 to a remote area. It is obvious that once the desired humidity is attained the humidistat 66 will open the circuit to prevent any fiow of additional water to be admitted through valve 58. The water in pan 22, when the firepot is not heated, or is at a low temperature, functions as an additional evaporator pan similar to pans 21).

From the above embodiment and drawing, herein clearly described and illustrated, it will be evident to those skilled in the art that various modifications may be made in the construction without departing from the principles herein set forth.

I claim:

1. A humidifier adapted for use with a forced air heating system having a casing With ducts therein comprising:

(a) a firepot positioned in the casing;

(b) a base pan in proximity with said firepot, said pan being of thin wall construction of a material having a high thermal conductivity and further having a bottom contour complementary to the firepot on which it is in proximity with;

(c) a hollow tube means extending from a central portion of said base pan, said tube means forming a support for a plurality of evaporator pans positioned thereabove;

(d) a plurality of evaporator pans positioned along said tube means in spaced apart relationship and extending from said tube means in a stacked arrangement whereby the pan above any respective pan is smaller in overall periphery than the pan located beneath it;

(e) means to supply water to a topmost evaporator pan comprising a water discharge line disposed above the said evaporator pan; and,

(f) means for limiting the amount of water in said base pan to a maximum of one-eighth of an inch, said means including a float chamber in communication with said base pan, a float member in said chamber having a stem extending therefrom, a switch attached to said float chamber, a solenoid actuated valve for controlling said water supply means, and, means to actuate said switch to thereby open said valve to allow water to be deposited in said evaporator pans.

2. A humidifier adapted for use with a forced air heating system having a casing with ducts therein comprising:

(a) a firepot positioned in the casing;

(b) a base pan mounted on said firepot, said pan having a bottom contour complementary to the firepot on which it is mounted, said pan further being constructed of thin wall material having a high thermal conductivity;

(c) a hollow tube means extending from a central portion of said base pan, said tube means forming a support for a plurality of evaporator pans positioned thereabove;

(d) a plurality of circular evaporator pans positioned along said tube means in spaced apart relationship and extending from said tube means in a stacked arrangement whereby the pan above any respective pan is smaller in overall diameter than the pan located beneath it;

(e) means to supply water to a topmost evaporator pan including a water discharge line disposed above one of said evaporator pans, valve means for controlling the water to said discharge line, and means to actuate said valve means; and

(f) means for regulating the amount of water in said base pan, said means including a float chamber in communication with said base pan, a float member in said chamber having a stern extending therefrom and adapted to actuate said water supply means.

3. A humidifier adapted for placement in the casing of a forced air furnace including:

(a) a circular base pan, said pan being of thin wall construction of a material having a high thermal conductivity;

(b) a plurality of circular evaporator pans, positioned one above the other in axial alignment, said pans decreasing in circumference the further their location from said base pan;

(c) a hollow tube means extending through the axis of said pans and forming a leakproof connection therebetween, said tube means forming a support for a plurality of evaporator pans positioned thereabove;

(d) means to supply water to a topmost one of said evaporator pans whereby upon filling, the water will subsequently overflow into said base pan, including a water discharge line disposed above one of said evaporator pans; and,

(e) means for controlling the amount of water in said base pan so that the level therein does not exceed one-eighth inch, said means including a float chamber in communication with said pan, a float member in said chamber having a stem extending therefrom adapted to actuate said water supply means.

References Cited by the Examiner UNITED STATES PATENTS 1,325,559 12/1919 Eckelmann. 1,458,549 6/1923 Sallada l26--1l3 1,862,985 6/1932 Sandwich et a1. 126-113 2,804,067 8/1957 Elgin 1261l3 3,151,615 10/1964 Siniaho 126113 JAMES W. WESTHAVER, Primary Examiner. 

1. A HUMIDIFIER ADAPTED FOR USE WITH A FORCED AIR HEATING SYSTEM HAVING A CASING WITH DUCTS THEREIN COMPRISING: (A) A FIREPOT POSITIONED IN THE CASING; (B) A BASE PAN IN PROXIMITY WITH SAID FIREPOT, SAID PAN BEING OF THIN WALL CONSTRUCTION OF A MATERIAL HAVING A HIGH THERMAL CONDUCTIVITY AND FURTHER HAVING A BOTTOM CONTOUR COMPLEMENTARY TO THE FIREPOT ON WHICH IT IS IN PROXIMITY WITH; (C) A HOLLOW TUBE MEANS EXTENDING FROM A CENTRAL PORTION OF SAID BASE PAN, SAID TUBE MEANS FORMING A SUPPORT FOR A PLURALITY OF EVAPORATOR PANS POSITIONED THEREABOVE; (D) A PLURALITY OF EVAPORATOR PANS POSITIONED ALONG SAID TUBE MEANS IN SPACED APART RELATIONSHIP AND EXTENDING FROM SAID TUBE MEANS IN A STACKED ARRANGEMENT WHEREBY THE PAN ABOVE ANY RESPECTIVE PAN IS SMALLER IN OVERALL PERIPHERY THAN THE PAN LOCATED BENEATH IT; (E) MEANS TO SUPPLY WATER TO A TOPMOST EVAPORATOR PAN COMPRISING A WATER DISCHARGE LINE DISPOSED ABOVE THE SAID EVAPORATOR PAN; AND, (F) MEANS FOR LIMITING THE AMOUNT OF WATER IN SAID BASE PAN TO A MAXIMUM OF ONE-EIGHT OF AN INCH, SAID MEANS INCLUDING A FLOAT CHAMBER IN COMMUNICATION WITH SAID BASE PAN, A FLOAT MEMBER IN SAID CHAMBER HAVING A STEM EXTENDING THEREFROM, A SWITCH ATTACHED TO SAID FLOAT CHAMBER, A SOLENOID ACTUATED VALVE FOR CONTROLLING SAID WATER SUPPLY MEANS, AND, MEANS TO ACTUATE SAID SWITCH TO THEREBY OPEN SAID VALVE TO ALLOW WATER TO BE DEPOSITED IN SAID EVAPORATOR PANS. 